Hi, I am using ChebyshevFunction to evaluate exp(x). But I encountered some error. My ciphertext - a can be decrypted into: [ 0.923663 -8.27976e-06 5.00274e-06 -9.2856e-06 -2.67874e-06 0.950437 0.999738 0.999993 -1.93079e-05 7.29427e-06 -1.34528e-05 -1.0477e-05 2.14772e-06 4.70038e-06 6.8613e-06 -…

firstModSize and scaling factor are way too small for the bootstrapping and a precise polynomial evaluation, try to use larger values (as the ones in the examples)

Thanks for your fast reply. I am using small values because I need to use some rotation keys for this program (other parts of the program), and they have large memory sizes. To use larger parameters, I need to find out how to reduce key sizes. (I created a new topic to follow up on that) Is there a …

I think that the ciphertext is already “done” after the bootstrapping, try to print it before the chebyshev evaluation.

Hi, my ciphertext is printed before bootstrapping, it comes from other parts of my program. Essentially, the ciphertext a in a = cc->EvalBootstrap(a); contains the value [ 0.923663 -8.27976e-06 5.00274e-06 -9.2856e-06 -2.67874e-06 0.950437 0.999738 0.999993 -1.93079e-05 7.29427e-06 -1.34528e-05 -1.0…

Yeah, but is it (almost) the same before and after the bootstrap?

Thanks for asking that, it raises a good point, when I try to decrypt after Bootstrap as following: cout << "ChebyshevFunction begin" << endl; double lowerBound = -2.0; double upperBound = 2.0; uint32_t polyDegree = 27; a = cc->EvalBootstrap(a); Plaintext outcome; cc->Decry…

ChebyshevFunction evaluation error

Library Questions

narger July 5, 2024, 7:43pm 8

You should increase firstModSize and dcrtBits (CKKS Bootstrapping gives incorrect results on scale != 60? - #4 by ypolyakov)

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ChebyshevFunction evaluation error

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